Re: [patch v2] mm, hugetlb: abort __get_user_pages if current has been oom killed

From: Kirill A. Shutemov
Date: Mon Mar 09 2015 - 07:24:52 EST


On Mon, Mar 09, 2015 at 12:42:15AM -0700, David Rientjes wrote:
> If __get_user_pages() is faulting a significant number of hugetlb pages,
> usually as the result of mmap(MAP_LOCKED), it can potentially allocate a
> very large amount of memory.
>
> If the process has been oom killed, this will cause a lot of memory to
> be overcharged to its memcg since it has access to memory reserves or
> could potentially deplete all system memory reserves.
>
> In the same way that commit 4779280d1ea4 ("mm: make get_user_pages()
> interruptible") aborted for pending SIGKILLs when faulting non-hugetlb
> memory, based on the premise of commit 462e00cc7151 ("oom: stop
> allocating user memory if TIF_MEMDIE is set"), hugetlb page faults now
> terminate when the process has been oom killed.
>
> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
> Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>

Acked-by: Kirill A. Shutemo <kirill.shutemov@xxxxxxxxxxxxxxx>

--
Kirill A. Shutemov
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